#include<bits/stdc++.h>
using namespace std;
#define ll long long

const int mod=1e9+7;

ll K(ll x,ll y=mod-2){
    ll t=1;
    for (;y;y>>=1,x=x*x%mod)
        if (y&1) t=t*x%mod;
    return t;
}

int T, n;

int main(){
    for (cin>>T;T--;){
        int n, ans, p; cin>>n;
        cin>>p; --n; ans=p/2;
        for (;n--;){
            int x; cin>>x;
            ll t=(1-(K(2)+K(x)*(p/2))%mod+mod)*(x/2)%mod;
            ans=(ans+t)%mod;
            p=x;
        }
        cout<<ans<<endl;
    }
}